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Posted: 7/4/2012 5:50:14 PM EDT
| Just finished my first reloads. 150 rounds of 45 auto. Using a Hornady Classic press kit. My question is how repeatable should the powder measurer be? My experience on this first 150 was a lot of variance. I was weighing each load and would get two or three and then it would jump. The range was 5.8 to 7.2 grains. The powder was Winchester 231. I was using the pistol metering accessory. Just wondering what my expectations should be and if I'm doing something wrong. Thanks in advance for the help! |
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There are tricks to getting a powder measure to be as predictable as possible.
Wacking it with a wrench now and then settles the powder and can help. Keep it full to a consistent level also matters. When they run low they tend to throw light. Then there are the proper uses of a baffle. The first few throws are usually good to scrap in the name of consistency (into a tricker, for example). You should be able to detect if some powder gets stuck in the funnel and the charge hangs. |
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Something's not right, you shouldn't have that large a difference. One of the most important thing about using a manual powder measure is that you always use the exact same technique when you throw a load. It could be a knock on the upswing, or a knock and a pause or a knock when you lower the lever. Throw 10 loads using an identical motion on each one, then look at your variance. |
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Constant throws is a matter of technique. Basics, Settle powder in hopper by tapping hopper with finger. Watch powder settle. (Otherwise this process will take 10-15 thrown charges) Throw 3 charges in pan, and return them to hopper. Now you have the powder settled and throw and weigh a charge. Use same motion/speed/force with each charge you throw. This is the secret. When you adjust PM, throw 3 charges in pan, and return them to hopper. After each adjustment powder need to settle again. Finally, you have to practice. Your Hornady measure will throw + or_ .1 grain with W-231 with the right technique.  |
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That's 1.4 grains variance.
I shut the show off at 3/10ths of a grain using Hornady powder drop with pistol rotor. Even if using rifle rotor I wouldn't see that kind of spread, regardless of technique. First thing I do with a new powder measure is, Wash all plastic parts in hot, soapy dishwater Spray all metal parts clean with brake cleaner. In fact I've been known to drop everything in scalding hot dish water. Wash Wipe dry, allowing plastic to air dry and spraying metal parts completely to rid of remaining moisture if any. Then reassemble and go again. At 1.4 grains variance you were surrounded by red lights, or should have been. |
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Quoted:
..... Wash all plastic parts in hot, soapy dishwater Spray all metal parts clean with brake cleaner. In fact I've been known to drop everything in scalding hot dish water. Wash Wipe dry, allowing plastic to air dry and spraying metal parts completely to rid of remaining moisture if any. Then reassemble and go again. ....... ^^^ What he said. Plus, it'll run smoother after a pound or so of powder has been run through it as some of the coating on the powder particles will "lubricate" the measure. I've heard of people using graphite to do this, but you can just cycle the measure a bunch of times for the same effect. |
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Camdex machines will hold variance to within 3/10ths grain.
This I am told by an ammunition manufacturer who runs a few. His test groups are 30 shots at 25 yards all holding within 3" of the test targets he showed me. Chasing that rabbit a little farther into it's hole is ES and SD. I load match ammunition to within three tenths of a tenth grain to ride low side of power factor. If cartridges can't pass chronographs I'm disqualified from regional or national match. Entry fees in these matches range $50.00 to $300.00. Then there's the cost of getting to match and equipment. Loading for local matches doesn't require powder to be all that exact. |
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Quoted:
Kind of on the same subject here, how much variance can you have in your powder measure before it starts to affect accuracy? I've read up to 3% with little or no change. I'm sure the type of powder would make a difference....3% of Bullseye would be way different than 3% of Unique. |
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Quoted:
Kind of on the same subject here, how much variance can you have in your powder measure before it starts to affect accuracy? For most pistol loads I wouldn't expect .2grains to have noticeable accuracy changes but I would aim more for .1gr I have always favored the old time lyman powder measure (#55?) as it has the little toggle thingy that you pop with your finger to settle the powder or make sure all the powder is dropping. Be consistent with the way you operate the measure and keep the hopper at least 1/2 full |
| You can attach a small aquarium air pump to the side of the powder measure. The vibration will help the powder to settle in the charge bar more consistently. You can also run an air tube off of the pump blowing on the shell plate to blow off spilled powder/brass shavings/etc. |
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Quoted: You can attach a small aquarium air pump to the side of the powder measure. The vibration will help the powder to settle in the charge bar more consistently. You can also run an air tube off of the pump blowing on the shell plate to blow off spilled powder/brass shavings/etc. Vibrating tooth brush works for me. And they are only $5. |
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I really appreciate the responses. First, it was a digital scale. The small cheap one that came with the kit. I cleaned the powder measurer twice, but not in soapy water, just the case lube/cleaner that Hornady recommended. I think I will take the advice of a very thorough cleaning in soapy water before I use it again. I also like the idea of the electric toothbrush, so I'll also try that.
Okay now for the really stupid follow-up question. How is the baffle (mine came with one) suppose to be orientated in the measurer's tube? |
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I think the most likely cause has been overlooked. Most likely you are using the universal rotor and a pistol metering assembly, you need to be using a specialized pistol rotor and pistol metering assembly. The universal rotors just don't work well with small charges of pistol powder! http://www.hornady.com/store/Pistol-Rotor-and-Metering-Assy-1-Each/ |
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Quoted: I really appreciate the responses. First, it was a digital scale. The small cheap one that came with the kit. I cleaned the powder measurer twice, but not in soapy water, just the case lube/cleaner that Hornady recommended. I think I will take the advice of a very thorough cleaning in soapy water before I use it again. I also like the idea of the electric toothbrush, so I'll also try that. Okay now for the really stupid follow-up question. How is the baffle (mine came with one) suppose to be orientated in the measurer's tube? Cheap digital scales ( IMO those that cost under $100) drift. Means that the scale will not read the same powder charge the same twice. Try it yourself. Drop a change, weigh it. Take off scale and place back on scale. Same reading? There's most of your problem. I'm a beam scale guy, but they do make good digital's I hear.
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